Exercise Can Improve Your Brain…Even More Than Using Your Brain

Last weekend’s New York Times Magazine contained several articles about the mind, and all the cutting edge research out there about how to improve the mind. One article detailed how playing “n-back games” can make you smarter; another about how exercise can lead to a better brain. Several studies have detailed how exercise can improve brain function, mood, and even improve memory in the past, but the newest research seems to seal the deal: Exercise really, actually does improve your brain…and for now, I’m going to wage my bets on exercise over n-back games.

Past research has implied all kinds of mental benefits of exercise, but until recently, scientists hadn’t really parsed out the difference in effect of putting on our running shoes and, say, playing a board game. But last year, Justin S. Rhodes, a psychology professor at the Beckman Institute for Advanced Science and Technology at the University of Illinois, led a study that teased out the differences. Rhodes’ team performed cognitive tests on four groups of mice, then injected them with a substance that allowed for tracking neurological changes, and put them into four distinct living arrangements:

Group 1 was fed a gourmet diet of nuts, fruits and cheeses sometimes dusted with cinnamon, served with flavored waters. They slept in colorful plastic igloos in one corner of their cage, and were given neon balls, tunnels, mirrors and seesaws to play with in another section of the cage.

Group 2 had all of the above, plus disc-shaped running wheels in their cages.

Group 3 had no toys or exercise equipment, and were fed standard kibble.

Group 4 had nothing to play with but a running wheel, and was fed standard kibble—no gourmet treats.

After several months of running, playing, or lazing around their cages, the mice were given the same cognitive test that was administered at the start of the study, and researchers examined their brain tissues. Though we’re guessing the toys and gourmet treats made some mice a lot happier than others, the end result was that nothing improved brain function, except for running. According to the Times:

“Only one thing had mattered,” Rhodes says, “and that’s whether they had a running wheel.” Animals that exercised, whether or not they had any other enrichments in their cages, had healthier brains and performed significantly better on cognitive tests than the other mice. Animals that didn’t run, no matter how enriched their world was otherwise, did not improve their brainpower in the complex, lasting ways that Rhodes’s team was studying. “They loved the toys,” Rhodes says, and the mice rarely ventured into the empty, quieter portions of their cages. But unless they also exercised, they did not become smarter.

That’s because exercise stimulates neurogenesis—the body’s natural production of new neurons in the brain—and it seems to help those new neurons plug into the existing neural network; a process that’s necessary in order for those new neurons to do any good. And although other activities, like learning a new language, can help link new neurons into our neural networks, scientists say that those neurons are then pretty much only fired up by practicing that activity; running, on the other hand, creates neurons that link in and activate in response to several activities (not just running).

Researchers are still investigating the exact process by which all of this happens in the body and brain, but the end result is better cognitive function and significantly slower decline of brain function with age.

Meanwhile, other researchers are trying hard to prove that mind games can actually make you smarter—an intriguing claim in its own right. But research there is less conclusive, and while playing iPhone games to make yourself smarter is a nice idea in theory, in practice, it feels a lot like sitting around watching TV—I’d rather go for a run.